In thermal printing, it is generally well known to render images by heating and pressing one or more donor materials such as a dye, colorant or other coating against a receiver medium. The donor materials are provided in sized donor patches on a movable web known as a donor ribbon. The donor patches are organized on the ribbon into donor sets, each set containing all of the donor patches that are to be used to record an image on the receiver medium. For full color images, multiple color dye patches can be used, such as yellow, magenta and cyan donor dye patches. Arrangements of other color patches can be used in like fashion within a donor set. Additionally, each donor set can include an overcoat or sealant layer
It will be appreciated from this that in conventional thermal printers the size of the donor media patches defines the maximum size of full size image that can be printed using thermal printer. To provide flexibility of use, many thermal printers are capable of printing relatively large images such as 6″×8″ images. While prints of this size are highly desirable for many uses, it can be challenging to use and store images printed at this size. Accordingly, consumers often request that such printers render images at a fraction of the full size image, such as images printed at the wallet size, 3″×5″ size or 4″×6″ size. Images at these sizes are more easily used and stored and require only a fraction of the donor material from a donor patch set.
Unfortunately, the printers of the prior art are not adapted to use the donor material from the fractional donor patch set for printing other images. Instead, it is conventionally known to have a thermal printer advance to the next complete donor set after printing a fractional size image so that the thermal printer is prepared to print any size image when the next printing order is received. It will be appreciated that this results in inefficient use of the donor material by causing increased printing costs. What is needed therefore is a method and system that enable more efficient use of donor material in a printing system.